Anhydrous ammonia pulmonary toxicity: A significant farming hazard

Irfan Waheed MD, Audra Fuller MD

ABSTRACT

Anhydrous ammonia is a toxic gas widely used as a fertilizer. In 2016 about 12 million tons of ammonia were used in the production of fertilizers. We are reporting a case of severe pulmonary toxicity from anhydrous ammonia fertilizer exposure. An 80-year-old male farmer was accidentally exposed to anhydrous ammonia released from a pressurized fertilizer tank. He was intubated due to upper airway inhalation injury. Bronchoscopy showed extensive lower airway mucosal damage. The sloughed bronchial mucosa was removed from obstructed bronchi using a cryoprobe. He developed acute respiratory distress managed with lung protective mechanical ventilation. He did not improve and tracheostomy was recommended. The patient’s family opted for comfort care only. Anhydrous ammonia can cause pulmonary toxicity. Symptoms range from mild to severe and can be fatal at doses greater than 5,000 parts per million. Early inspection of the upper respiratory tract and securing an airway are lifesaving. Management is supportive with oxygen and mechanical ventilation. Education, the use of protective gear, and proper equipment handling are key steps in the prevention of accidental toxicity.